Floating LNG terminals are a relatively new concept with the first such terminal in the world installed this year. The hydrodynamic interaction effects between the terminal and a LNG carrier in a side-by-side offloading arrangement is investigated. The side-byside arrangement is compared with each body floating alone to identify the interaction effects. The hydrodynamic coefficients are obtained using the Constant Panel Method and the analysis of body motions, mooring line tensions are done in time domain. The relative motion between the two bodies is analyzed using WAMIT in frequency domain and WINPOST in time domain to ascertain the offloading operability of the terminal under 1 year storm condition.

A floating quay container terminal is used for loading or unloading from container ships from both sides of a floating quay. The side-by-side Liquefied Natural Gas (LNG) offloading operation from floating terminals to LNG carriers is very similar to that from super-container ships to floating quay-walls. The hydrodynamic interaction effects among a fixed quay, container ship and floating quay, which are parallel to one another, are investigated. The three body side-by-side arrangement is compared with the individual freely floating body in the absence/presence of the fixed quay to identify the interaction effects. Hydrodynamic coefficients of the interacting bodies are obtained using a three dimensional constant panel method, WAMIT. Using a vessel-lines coupled dynamic analysis computer program WINPOST, the relative motion between floating quay and container ship is simulated in time domain. It is assumed in the present study that the floating quay is positioned by a dolphin mooring system. This analysis provides the relative motion among container ship, fixed and floating quay to ascertain that container loading and offloading can be performed in the severe wave condition without any problem.

No description available.

This thesis examines a floating gate device (FGD) structure available under standard (digital) CMOS manufacturing processes and puts forth two applications for these devices. The first application is the creation of a tunable current mirror. Inclusion of the FGD structure allows the legs of the mirror to be electronically tweaked to compensate for mismatch. Experimental data is presented on this device structure?s performance. The second application explores using the FGD structure as a tunable resistor. Operation of the FGD in this manner creates the possibility of an electrically tunable beta-multiplier current reference. This tunability allows theoretical adjustment of both the generated reference current as well as a selectable temperature performance. Experimental data of obtained resistor values is presented with simulation results of the entire circuit.

Floating wind turbines (FWTs) are considered a new lease of opportunity for sustaining growth from offshore wind energy. In recent years, several new concepts have emerged, with only a few making it to demonstration or pre-commercialisation stages. Amongst these, the spar-buoy based FWT has been extensively researched concept with efforts to optimise the dynamic response and reduce the costs at acceptable levels of performance. Yet, there exist notable lapses in understanding of these systems due to lack of established design standards, operational experience, inaccurate modelling and inconsistent reporting that hamper the design process. Previous studies on spar-buoy FWTs have shown inconsistencies in reporting hydrodynamic response and adopted simplified mooring line models that have failed to capture the coupled hydrodynamic behaviour accurately. At the same time, published information on drive-trains for FWTs is scarce and limited to geared systems that suffer from reliability issues. This research was aimed at filling the knowledge gaps with regard to hydrodynamic modelling and drive-train research for the spar-buoy FWT. The research proceeds in three parts, beginning with numerical modelling and experimental testing of a stepped spar-buoy FWT. A 1:100 scale model was constructed and tested in the University of Edinburgh’s curved wave tank for various regular and irregular sea states. The motion responses were recorded at its centre of mass and nacelle locations. The same motions were also simulated numerically using finite element method based software, OrcaFlex for identical wave conditions. The hydrodynamic responses were evaluated as Response Amplitude Operator (RAO) and compared with numerical simulations. The results showed very good agreement and the numerical model was found to better capture the non-linearities from mooring lines. A new design parameter, Nacelle Magnification Factor, was introduced to quantify coupled behaviour of the system. This could potentially encourage a new design approach to optimising floating wind turbine systems for a given hub height. The second part of the research was initiated by identification of special design considerations for drive-trains to be successfully integrated into FWTs. A comparative assessment of current state of the art showed good potential for directdrive permanent magnet synchronous generators (PMSG). A radial flux topology of the direct-drive PMSG was further examined to verify its suitability to FWT. The generator design was qualified based on its structural integrity and ability to ensure minimal overall impact. The results showed that limiting the generator weight without compromising air-gap tolerances or tower-foundation upgrades was the biggest challenge. Further research was required to verify the dynamic response and component loading to be at an acceptable level. The concluding part of research investigated the dynamic behaviour of the directdrive generator and the various processes that controlled its performance in a FWT. For this purpose, a fully coupled aero-hydro-servo-elastic model of direct-drive FWT was developed. This exercise yet again highlighted the weight challenge imposed by the direct-drive system entailing extra investment on structure. The drive-train dynamics were analysed using a linear combination of multi-body simulation tools namely HAWC2 and SIMPACK. Shaft misalignment, its effect on unbalanced magnetic pull and the main bearing loads were examined. The responses were found to be within acceptable limits and the FWT system does not appreciably alter the dynamics of a direct-drive generator. Any extra investment on the structure is expected to be outweighed by the superior performance and reliability with the direct-drive generator. In summary, this research proposes new solutions to increase the general understanding of hydrodynamics of FWTs and encourages the implementation of direct-drive generators for FWTs. It is believed that the solutions proposed through this research can potentially help address the design challenges of FWTs.

<p>Det moderna informationssamhället har medfört en ökning av upplevd stress. Avslappningsmetoder används som ett sätt att motverka hög anspänning. En relativt ny företeelse utgör floating, där man flyter i saltkoncentrerat vatten inuti en stimulireducerad flyttank. Forskning har påvisat gynnsamma effekter av floatingutövande. Syftet i denna studie var att undersöka individers upplevelser av att ligga i en flyttank. Sex halvstrukturerade intervjuer gjordes med floatingutövare som flyter med varierande grad av sensorisk restriktion. Tematisk analys användes i databearbetningen. Resultaten visade att floating upplevdes som behagligt och avslappnande. Stora skillnader förelåg dock mellan individer i flera aspekter av floatingupplevelsen. Graden av sensorisk reducering i flyttanken tycktes påverka typen av erfarenheter. Ovanliga upplevelser var endast förekommande vid floating med strikt stimulireduktion. Ett vetenskapsteoretiskt resonemang förs kring synen på ovanliga upplevelser. Floatingens användbarhet som terapeutiskt verktyg diskuteras och vidare forskning kring floating och terapi rekommenderas.</p>

No description available.

Hurricanes rapidly destroy large expanses land in coastal Louisiana marsh. Research shows that freshwater marsh with organic soils experience increased destruction during hurricanes compared to other marsh. A relevant question surfaces, do some restoration projects create marsh similar to marshes that are more susceptible to hurricane damage. This study analyzes soil, bulk density, plant composition, and buoyancy of restoration projects and sites adjacent to those that experienced land loss during Hurricanes Katrina and Rita. Results indicate that high organic matter percentages in marsh soil increases hurricane susceptibility attributed to decreased bulk density and increased buoyancy. Buoyancy is episodic and is highest during late summer months when soil temperature and decomposition are highest. Late summer is typically when most intense hurricanes occur. If marsh is less dense, decomposing, and buoyant when strongest hurricanes hit, then potential for destruction during a hurricane increases. Samples were collected from August 2009 to October 2009.

The U-curves of five different test objects, three of which contain a rod floating object at different positions within the gap, are characterised. During the testing, a high speed camera was used to photograph the discharges. The results are compared to Rizk’s theoretical model for determining the flashover voltage of gaps with floating objects are presented. It is concluded that the position of the floating object within the gap affects which discharge mechanism exists in each of the gaps. The effect that each discharge mechanism has on the flashover voltage and time to crest of the gap is shown. Time interval photographs are presented showing the formation of a discharge channel due to the streamer mechanism. In evaluating the high speed photographs it is seen that the extent of the branching of the discharge channel is a function of the time to crest of the applied impulse, more branching is evident for shorter times to crest.

Ho Chun Hok. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 74-78). / Abstracts in English and Chinese. / Abstract --- p.ii / Acknowledgement --- p.v / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Motivation --- p.1 / Chapter 1.2 --- Aims --- p.3 / Chapter 1.3 --- Contributions --- p.3 / Chapter 1.4 --- Thesis Organization --- p.4 / Chapter 2 --- Background and Literature Review --- p.5 / Chapter 2.1 --- Introduction --- p.5 / Chapter 2.2 --- Field Programmable Gate Arrays --- p.5 / Chapter 2.3 --- Traditional design flow and VHDL --- p.6 / Chapter 2.4 --- Single Description for Hardware-Software Systems --- p.7 / Chapter 2.5 --- Parameterized Floating Point Arithmetic Implementation --- p.8 / Chapter 2.6 --- Function Approximations by Table Lookup and Addition --- p.9 / Chapter 2.7 --- Summary --- p.10 / Chapter 3 --- Floating Point Arithmetic --- p.11 / Chapter 3.1 --- Introduction --- p.11 / Chapter 3.2 --- Floating Point Number Representation --- p.11 / Chapter 3.3 --- Rounding Error --- p.12 / Chapter 3.4 --- Floating Point Number Arithmetic --- p.14 / Chapter 3.4.1 --- Addition and Subtraction --- p.14 / Chapter 3.4.2 --- Multiplication --- p.17 / Chapter 3.5 --- Summary --- p.17 / Chapter 4 --- FLY - Hardware Compiler --- p.18 / Chapter 4.1 --- Introduction --- p.18 / Chapter 4.2 --- The Fly Programming Language --- p.18 / Chapter 4.3 --- Implementation details --- p.19 / Chapter 4.3.1 --- Compilation Technique --- p.19 / Chapter 4.3.2 --- Statement --- p.21 / Chapter 4.3.3 --- Assignment --- p.21 / Chapter 4.3.4 --- Conditional Branch --- p.22 / Chapter 4.3.5 --- While --- p.22 / Chapter 4.3.6 --- Parallel Statement --- p.22 / Chapter 4.4 --- Development Environment --- p.24 / Chapter 4.4.1 --- From Fly to Bitstream --- p.24 / Chapter 4.4.2 --- Host Interface --- p.24 / Chapter 4.5 --- Summary --- p.26 / Chapter 5 --- Float - Floating Point Design Environment --- p.27 / Chapter 5.1 --- Introduction --- p.27 / Chapter 5.2 --- Floating Point Tools --- p.28 / Chapter 5.2.1 --- Float Class --- p.29 / Chapter 5.2.2 --- Optimization --- p.31 / Chapter 5.3 --- Digital Sine-Cosine Generator --- p.33 / Chapter 5.4 --- VHDL Floating Point operator generator --- p.35 / Chapter 5.4.1 --- Floating Point Multiplier Module --- p.35 / Chapter 5.4.2 --- Floating Point Adder Module --- p.36 / Chapter 5.5 --- Application to Solving Differential Equations --- p.38 / Chapter 5.6 --- Summary --- p.40 / Chapter 6 --- Function Approximation using Lookup Table --- p.42 / Chapter 6.1 --- Table Lookup Approximations --- p.42 / Chapter 6.1.1 --- Taylor Expansion --- p.42 / Chapter 6.1.2 --- Symmetric Bipartite Table Method (SBTM) --- p.43 / Chapter 6.1.3 --- Symmetric Table Addition Method (STAM) --- p.45 / Chapter 6.1.4 --- Input Range Scaling --- p.46 / Chapter 6.2 --- VHDL Extension --- p.47 / Chapter 6.3 --- Floating Point Extension --- p.49 / Chapter 6.4 --- The N-body Problem --- p.52 / Chapter 6.5 --- Implementation --- p.54 / Chapter 6.6 --- Summary --- p.56 / Chapter 7 --- Results --- p.58 / Chapter 7.1 --- Introduction --- p.58 / Chapter 7.2 --- GCD coprocessor --- p.58 / Chapter 7.3 --- Floating Point Module Library --- p.59 / Chapter 7.4 --- Digital sine-cosine generator (DSCG) --- p.60 / Chapter 7.5 --- Optimization --- p.62 / Chapter 7.6 --- Ordinary Differential Equation (ODE) --- p.63 / Chapter 7.7 --- N Body Problem Simulation (Nbody) --- p.63 / Chapter 7.8 --- Summary --- p.64 / Chapter 8 --- Conclusion --- p.66 / Chapter 8.1 --- Future Work --- p.68 / Chapter A --- Fly Formal Grammar --- p.70 / Chapter B --- Original Fly Source Code --- p.71 / Bibliography --- p.74